Heat dissipation device

ABSTRACT

A heat dissipation device includes a fan module, a first plate structure and a fin assembly. The fan module includes a fan outlet. The first plate structure is disposed at the fan outlet. The thermal conductance of the first plate structure is above 100 W/(m·K). The first plate structure includes a heat-absorbing and a heat-dissipation surface. The heat-absorbing surface includes a heat-absorbing region in thermal contact with a heat source. The heat-dissipation surface includes a heat-dissipation region. The fin assembly is disposed on the heat-dissipation surface and in thermal contact with the heat-dissipation surface. The fan module is adapted to exhaust an air flow flowing above the heat-dissipation surface via the fan outlet. The air flow flows through the heat-dissipation region before through the fin assembly. The distance between the fan outlet and the heat-dissipation region is greater than the distance between the fan outlet and the fin assembly.

CROSS-REFERENCE TO RELATED APPLICATIONS

This non-provisional application claims priority under 35 U.S.C. §119(a) on Patent Application No(s). 201210375709.0 filed in China, P.R.C. on Sep. 29, 2012, the entire contents of which are hereby incorporated by reference.

BACKGROUND

1. Technical Field

The disclosure relates to a heat dissipation device, and more particularly to a heat dissipation device applicable to an advanced mobile electronic unit.

2. Related Art

With the development of functions of electronic product, the electronic product has more and more electronic units. With the number of the electronic units is increased, the heat generating power of each electronic unit is increased accordingly. Therefore, people gradually concern about the heat-dissipation problem. This kind of problem is much more important for a compact electronic product, i.e. laptop, tablet computer or a handheld telecommunication device.

When it comes to heat dissipation, a heat dissipation module is provided to perform heat dissipation to a heated electronic unit directly. The heat dissipation module adapted by a laptop consists of a fan module, a heat pipe, and a fin assembly. An end of the heat pipe is in thermal contact with the electronic unit via a copper component, and another end of the heat pipe is in thermal contact with the fin assembly. The heat dissipation module transfer the heat generated by the heat pipe to the fin assembly by the heat pipe and enables an air flow produced by the operation of the fan module to perform heat exchange with fin assembly to discharge the heat to surroundings, thereby dissipating heat from the heated electronic unit.

Speaking of the design of the structure, the space of conventional electronic device may enable to contain the above-mentioned stacked structure including the heat pipe and the copper component. However, when the electronic device is developed towards compactness and miniaturization, this stacked structure of the heat dissipation module may not satisfy the demand for thin thickness and high heat dissipation property.

SUMMARY

An embodiment of the disclosure provides a heat dissipation device, comprising a fan module, a first plate structure and a fin assembly. The fan module includes a fan outlet. The first plate structure is disposed at the fan outlet. The thermal conductance of the first plate structure is greater than or equal to 100 W/(m·K). The first plate structure includes a heat-absorbing surface and a heat-dissipation surface. The heat-absorbing surface includes a heat-absorbing region for being in thermal contact with a heat source. The heat-dissipation surface includes a heat-dissipation region. The fin assembly is disposed on the heat-dissipation surface and in thermal contact with the heat-dissipation surface. The fan module is adapted to exhaust an air flow flowing above the heat-dissipation surface via the fan outlet. The air flow flows through the heat-dissipation region before through the fin assembly. The shortest distance between the fan outlet and the heat-dissipation region is greater than the shortest distance between the fan outlet and the fin assembly.

BRIEF DESCRIPTION OF THE DRAWINGS

The present disclosure will become more fully understood from the detailed description given herein below for illustration only, and thus are not limitative of the present disclosure, and wherein:

FIG. 1 illustrates a schematic perspective view of a heat dissipation device according an embodiment of the disclosure;

FIG. 2 illustrates a schematic exploded view in FIG. 1;

FIG. 3 illustrates a schematic cross-sectional view along a 3-3 line in FIG. 1;

FIG. 4 illustrates a schematic view of a heat dissipation device according to another embodiment of the disclosure;

FIG. 5 illustrates a schematic perspective view of a heat dissipation device according yet another embodiment of the disclosure;

FIG. 6 illustrates a schematic cross-sectional view along a 6-6 line in FIG. 5; and

FIG. 7 illustrates a schematic view of a heat dissipation device according to still another embodiment of the disclosure.

DETAILED DESCRIPTION

Please refer to FIGS. 1 to 3. FIG. 1 illustrates a schematic perspective view of a heat dissipation device according an embodiment of the disclosure. FIG. 2 illustrates a schematic exploded view in FIG. 1. FIG. 3 illustrates a schematic cross-sectional view along a 3-3 line in FIG. 1. A heat dissipation device 100, for example, may be assembled in an electronic device and in thermal contact with an electronic unit 200 with high heat generating property for removing the heat generated by the electronic unit 200 in the electronic device. This electronic device, for example, may be a laptop, a personal digital assist (PDA), a tablet computer, or other mobile computing device pursing compactness or miniaturization. This electronic device, for example, may be a central processing unit (CPU), a graphic processing unit (GPU) or other electronic unit 200 with high heat generating property. The heat dissipation device 100 comprises a fan module 110, a first plate structure 120 and a fin assembly 130. The fan module 110 includes a fan outlet 112.

The first plate structure 120 is disposed at a fan outlet 112. The thermal conductance of the first plate structure 12 is greater than or equal to 100 W/(m·K). In this embodiment, the material of first plate structure 120 may be graphite, metal or other material whose thermal conductance is greater than or equal to 100 W/(m·K).

The first plate structure 120 includes a heat-absorbing surface 122 and a heat-dissipation surface 124. The heat-absorbing surface 122 and the heat-dissipation surface 124 are opposite to each other. The heat-absorbing surface 122 includes a heat-absorbing region 122 a which is used for being in thermal contact with a heat source. More specifically, the position, shape and size of the heat-absorbing region 122 a are the same as those of the region where the heat-absorbing surface 122 is in thermal contact with the electronic unit 200.

The heat-dissipation surface 124 includes a heat-dissipation region 124 a. The area of the heat-absorbing region 122 a is equal to the area of the heat-dissipation region 124 a. Furthermore, the shortest distance between the heat-absorbing region 122 a and the heat-dissipation region 124 a is greater than the shortest distance between the heat-absorbing region 122 a to another region of the heat-dissipation surface 124 except the heat-dissipation region 124 a. The shortest distance between the fan outlet 112 and the heat-dissipation region 124 a is greater than the shortest distance between the fan outlet 112 and any end of the fin assembly 130.

In this embodiment, the first plate structure 120 includes a convex region 126. The convex region 126 is used for containing the electronic unit 200 and being in thermal contact with the electronic unit 200. However, this embodiment is not limited to the structure of the first plate structure 120 which is in thermal contact with the electronic unit 200. In other embodiment, the first plate structure 120 may also be a flat plate which is in thermal contact with the electronic unit 200.

The fin assembly 130 is disposed on the heat-dissipation surface 124, and the fin assembly 130 is in thermal contact with the heat-dissipation surface 124.

The fan module 110 is adapted to discharge an air flow via the fan outlet 112. A portion of the air flow flows above the heat-dissipation surface 122 and this portion of the air flow flows through the heat-dissipation region 122 a before through the fin assembly 130. In some embodiments, the heat dissipation device 100 further comprises a second plate structure 140. The second plate structure 140, for example, may be a shell of the electronic device. The second plate structure 140 is disposed at the fan outlet 112. A gap D is formed between the first plate structure 120 and the second plate structure 140, and the fan outlet 112 is positioned between the first plate structure 120 and the second plate structure 140. Thus, the air flow, produced by fan module 110, is constrained between the first plate structure 120 and the second plate structure 140, which makes more air flows flow through the heat-dissipation region 122 a. In this embodiment, the material of the second plate structure 140 may be graphite, metal or other material whose thermal conductance is greater than or equal to 100 W/(m·K). In addition, the second plate structure 140 may be in thermal contact with the fin assembly 130, but not limited to the disclosure.

Furthermore, in some embodiments, the heat dissipation device 100 further comprises a first deflector 150. The fin assembly 130 includes a first end 132 and a second end 134. The first end 132 and the second end 134 are opposite to each other. The first end 132 is in the vicinity of the fan outlet 112. The second end 134 is farther away from the fan outlet 112 than the first end 132. The first deflector 150 is positioned between the first plate structure 120 and the second plate structure 140. The heat-absorbing region 112 a is disposed among the fan module 110, the first deflector 150 and the fin assembly 130. The first deflector 150 extends from the fan outlet to the second end 134 of the fin assembly 130 such that the first plate structure 120, the fin assembly 130 and the first deflector 150 form a channel together. The channel includes an air inlet and an exhaust outlet, and the channel also extends from the fan outlet 112 to the fin assembly 130 via the heat-dissipation region 124 a. The fan outlet 112 faces towards the air inlet. Furthermore, the fin assembly 130 is positioned at the exhaust outlet.

To sum up, the thermal conductance of the first plate structure 120 is greater than 100 W/(m·K). Therefore, when the heat generated by the electronic unit 200 enters the first plate structure 120 via the heat-absorbing region 122 a, the first plate structure 120 enables the heat to transfer to the heat-dissipation region 124 a from the heat-absorbing region 122 a rapidly. Since the air flow, produced by the fan module 110, flows through the heat-dissipation region 124 a before through the fin assembly 130, heat dissipation device 100 according to this embodiment may rapidly remove the heat generated by the electronic unit 200.

Please refer to FIG. 4, which illustrates a schematic view of a heat dissipation device according to another embodiment of the disclosure. The difference between a heat dissipation device 102 and the heat dissipation device 100 is that the heat dissipation device 102 further comprises a second deflector 160. The first deflector 150 and the second deflector 160 are positioned at two opposite sides of the first plate structure 120. The fin assembly 130 includes a first end and a second end which are opposite to each other. The first end is in the vicinity of the fan outlet 112. The second end is farther away from the fan outlet 112 than the first end. The second plate structure 140 is disposed on both of the first deflector 150 and the second deflector 160 such that the first plate structure 120, the second plate structure 140, the first deflector 150 and the second deflector 160 together form a channel 170 which includes an air inlet 172 and an exhaust outlet 174. The fan outlet 112 of the fan module 110 faces towards the air inlet 172 of the channel 170. The fin assembly 130 is disposed at the exhaust outlet 174, and the heat-dissipation region 122 a is positioned between the air inlet 172 and the exhaust outlet 174. Due to the above-mentioned design of the channel 170, an air flow, blown by the fan module 110, may guided by the channel 170 to flow through the heat-dissipation region 122 a before through the fin assembly 130.

Please refer to FIGS. 5 and 6, FIG. 5 illustrates a schematic perspective view of a heat dissipation device according yet another embodiment of the disclosure. FIG. 6 illustrates a schematic cross-sectional view along a 6-6 line in FIG. 5. The difference between a heat dissipation device 104 and the heat dissipation device 100 is that the structure of a first plate structure 120′ of the heat dissipation device 104 is different from that of the first plate structure 120. The first plate structure 120′ comprises a first plate component 120 a, a second plate component 120 b and a link plate component 120 c. The link plate component 120 c is connected to the first plate component 120 a and the second plate component 120 b. A gap D is formed between the first plate component 120 a and the second plate structure 140. The second plate component 120 b and the link plate component 120 c are both positioned in the gap D. A heat-absorbing region 122 a and a heat-dissipation region 124 a are positioned on two opposite surfaces of the second plate component 120 b, respectively. In the electronic device, the electronic unit 200 is positioned on a circuit board 300 and electrically connected to the circuit board 300. The first plate component 120 a is disposed on the circuit board 300, as well as the second plate component 120 b and the link plate component 120 c are both disposed between the circuit board 300 and the second plate structure 140 such that the circuit board 300, the second plate structure 140, the first deflector 150 and the fin assembly 130 together form a channel which includes an air inlet and an exhaust outlet. The fan outlet 112 faces towards the air inlet, and the fin assembly 130 is disposed at the exhaust outlet. Due to the above-mentioned design of the channel, an air flow, blown by the fan module 110, may be guided by the channel to flow through the heat-dissipation region 122 a before through the fin assembly 130.

From the embodiments shown in FIGS. 1, 4 and 5, the disclosure does not intend to limit the way of guiding the air flow generated by the fan module to flow through the heat-dissipation region. According to the design requirement, those of ordinary skills in the art may design the structure that guiding the air flow generated by the fan module to flow through the heat-dissipation region before through the fin assembly.

Please refer to FIG. 7, which illustrates a schematic view of a heat dissipation device according to still another embodiment of the disclosure. The difference between a heat dissipation device 106 and the heat dissipation device 100 is that the heat dissipation device 106 further comprises multiple third deflectors 190. The multiple third deflector 190 are all disposed on the heat-dissipation surface 124 of the first plate structure 120 and extend from an end of the first plate structure 120 in the vicinity of the fan outlet 112 towards the fin assembly 130. Therefore, the third deflector is adapted to guide an air flow generated by the fan module 110 to flow to the fin assembly 130 smoothly.

To sum up, the thermal conductance of the first plate structure is greater than 100 W/(m·K). Therefore, when the heat, generated by the electronic unit, enters the first plate structure via the heat-absorbing region, the first plate structure enables the heat to transfer to the heat-dissipation region from the heat-absorbing region. The air flow, produced by the fan module, first flows through the heat-dissipation region before trough fin assembly. Therefore, the heat dissipation device may rapidly remove the heat which is generated by the electronic unit.

Moreover, since the thermal conductance of the first plate structure is greater than or equal to 100 W/(m·K), when the heat, generated by the electronic unit, enters first plate structure via the heat-absorbing region, the first plate structure enables the heat from the heat-absorbing region to be distributed around each part of the first plate structure. Therefore, the fan module produces not only the air flow flowing to the fin assembly through the heat-dissipation region but also another air flow flowing to the fin assembly through the heat-dissipation surface to further remove the heat generated by the electronic unit.

Secondly, since the thermal conductance of the first plate structure is greater than or equal to 100 W/(m·K), the heat, generated by the electronic unit, may be rapidly transferred to fin assembly via the first plate structure. Because the air flow generated by the fan module is all guided to the fin assembly, the heat dissipation device may remove the heat generated by the electronic unit through the fin assembly.

Furthermore, compared to prior art, the heat dissipation device performs heat dissipation on the electronic unit by the thermal contact between the first plate structure and the electronic device such that the heat dissipation device dose not include a copper component and a heat pipe which are stacked together on the electronic unit in sequence. Therefore, the heat dissipation device is beneficial for the compactness and miniaturization of the electronic device.

The foregoing description of the exemplary embodiments of the invention has been presented only for the purposes of illustration and description and is not intended to be exhaustive or to limit the invention to the precise forms disclosed. Many modifications and variations are possible in light of the above teaching.

The embodiments were chosen and described in order to explain the principles of the invention and their practical application so as to activate others skilled in the art to utilize the invention and various embodiments and with various modifications as are suited to the particular use contemplated. Alternative embodiments will become apparent to those skilled in the art to which the present invention pertains without departing from its spirit and scope. Accordingly, the scope of the present invention is defined by the appended claims rather than the foregoing description and the exemplary embodiments described therein. 

What is claimed is:
 1. A heat dissipation device, comprising: a fan module including a fan outlet; a first plate structure disposed at the fan outlet, the thermal conductance of the first plate structure being greater than or equal to 100 W/(m·K), the first plate structure including a heat-absorbing surface and a heat-dissipation surface, the heat-absorbing surface including a heat-absorbing region for being in thermal contact with a heat source, the heat-dissipation surface including a heat-dissipation region; and a fin assembly disposed on the heat-dissipation surface, and the fin assembly being in thermal contact with the heat-dissipation surface, the fan module being adapted to exhaust an air flow flowing above the heat-dissipation surface via the fan outlet, wherein the air flow flows through the heat-dissipation region before through the fin assembly, and wherein the shortest distance between the fan outlet and the heat-dissipation region is greater than the shortest distance between the fan outlet and the fin assembly.
 2. The heat dissipation device according to claim 1, wherein the material of the first plate structure is graphite.
 3. The heat dissipation device according to claim 1, further comprising a second plate structure disposed at the fan outlet, wherein a gap is formed between the first plate structure and the second plate structure, and wherein the fan outlet is positioned between the first plate structure and the second plate structure.
 4. The heat dissipation device according to claim 1, wherein the thermal conductance of the second plate structure is greater than 100 W/(m·K).
 5. The heat dissipation device according to claim 4, wherein the thermal conductance of the second plate structure is graphite.
 6. The heat dissipation device according to claim 3, further comprising a first deflector, the fin assembly including a first end and a second end opposite to each other, the first end being in the vicinity of the fan outlet, the second end being farther away from the fan outlet, the first deflector positioned between the first plate structure and the second plate structure, the heat-absorbing region positioned among the fan module, the first deflector and the fin assembly, the first deflector being extending from the fan outlet to the second end of the fin assembly, wherein the first plate structure, the first deflector and the fin assembly together form a channel including an air inlet and an exhaust outlet, and wherein the fan outlet faces towards the air inlet, and the fin assembly is disposed at the exhaust outlet.
 7. The heat dissipation device according to claim 6, wherein the first plate structure further comprises a first plate component, a second plate component and a link plate component connected to the first plate component and the second plate component, the first plate structure is disposed on a circuit board, the heat-absorbing surface and the heat-absorbing region is positioned on the second plate component, the second plate component and the link plate component are disposed between the circuit board and the second plate structure, wherein the circuit board, the second plate structure, the first deflector and the fin assembly together form a channel including an air inlet and an exhaust outlet, the fan outlet faces towards the air inlet, and the fin assembly is disposed at the exhaust outlet.
 8. The heat dissipation device according to claim 3, further comprising a first deflector and a second deflector disposed at two opposite sides of the first plate structure, respectively, the fin assembly including a first end and a second end opposite to each other, the first end being in the vicinity of the fan outlet, the second end being in vicinity of the fan outlet, the second plate structure disposed on the first deflector and the second deflector such that the first plate structure, the second plate structure, the first deflector and the second deflector together form a channel including an air inlet and an exhaust outlet, the fan outlet faces towards the air inlet, and the fin assembly is disposed at the exhaust outlet.
 9. The heat dissipation device according to claim 3, wherein the first plate structure comprises a first plate component, a second plate component and a link plate component connected to the first plate component and the second plate component, the gap is positioned between the first plate component and the second plate structure, the second plate component is positioned at the gap, and the heat-absorbing region and the heat-dissipation region are disposed at two opposite surfaces of the second plate component.
 10. The heat dissipation device according to claim 1, further comprising a third deflector disposed on the heat-dissipation surface of the first plate structure and extending from an end of the first plate structure on the vicinity of the fan outlet towards the fin assembly. 